Methods of mounting electronic components onto a wiring board have focused on streamlining the mounting jobs, and also on alleviating the environmental load as a lead-free soldering. Under such a climate, a press-fit fixing terminal is employed to some mounting methods instead of soldering.
This conventional press-fit fixing terminal is described with reference to FIG. 6–FIG. 8. FIG. 6 shows a front view of the conventional terminal, and FIG. 7 shows a lateral view of the terminal shown in FIG. 6. FIG. 8 shows a schematic sectional view cut along line 8—8 of FIG. 6, namely, a schematic sectional view illustrating the press-fit fixing terminal mounted to a wiring board. In FIG. 6, press-fit fixing terminal 301 is attached to electronic component 302, and terminal 301 is formed symmetrically with respect to a center axis of an inserting direction to the wiring board.
Press-fit fixing terminal 301 has hollow section 303 formed by blanking along the outline thereof. Terminal 301 is formed of two lines, and each one of the lines includes extending section 304 linearly extends from the root of electronic component 302, straddling section 305 which flares gradually from extending section 304 to ridges 306, and terminal segments 307 which tapers off from ridges 306 to tip of terminal 301.
As shown in FIG. 7, the one line formed of straddling section 305 and terminal segment 307 is bent, thereby forming a V-shaped wedge, the other line formed of straddling section 305 and terminal segment 307 is bent in the same way, so that the two lines are spaced out widest at ridges 306.
Press-fit fixing terminal 301 discussed above is press-fitted into through-hole 308 provided to wiring board 309 as shown in FIG. 8. The inner diameter of through-hole 308 is slightly smaller than the maximum width between two ridges 306 in order to maintain the mechanical and electrical connections of terminal 301.
Prior art related to the present invention is disclosed in, e.g. Unexamined Japanese Patent Publication No. 2003-257526.
As shown in FIG. 8, conventional press-fit fixing terminal 301 has two ridges 306 which are brought into contact with through-hole 308 at the insertion, and ridges 306 are the cut-faces or the corners produced by blanking press-fit terminal 301 out of the material metal plate, so that the ground of the material contacts through-hole 308. In order to get stable electrical contact, terminal 301 undergoes a plating process after the blanking. The plating process incurs an additional cost and sometimes invites deformation.